Geez! Tim, you do have a good copy of that lens. In this shot at least, the image looks sharp from corner to corner. This was not the case with the 3 lenses that I tested in a store in Bangkok a couple of years ago on my way to Angkor Wat. I wanted something wider than my Sigma 15-30, but had read about the 12-24 quality variations so made a special point of testing some copies in the store before buying.

All three were significantly softer towards the edges, at 15mm, than my Sigma 15-30, so I didn't buy. The lenses were about equal in the centre though.

I think this is pretty good copy of a lens with a bit of production quality variation (from what I read). In any event, it's noticeably better than my 16-35 (and Sigma 14 - which goes without saying).[a href=\"index.php?act=findpost&pid=158519\"][{POST_SNAPBACK}][/a]

Yikes, that's superb. I was going to geet a 17-40L, but I think you've just changed my mind. I tried one once and didn't really like the focus and zoom rings, but maybe it's worth getting used to to get the wider angle coverage and corner sharpness.

Though there is some odd mottling/artifacting in the image, is that from the JPEGing? Thogh it's not exactly a small Jpeg! Look above the Galleria Offices sign on right of image to see what I mean.[a href=\"index.php?act=findpost&pid=158633\"][{POST_SNAPBACK}][/a]

Hmmm, at ISO 400 I didn't look much for noise - I'll have to watch for that. Jpg at 11, so I don't think it's that...

Hmmm, at ISO 400 I didn't look much for noise - I'll have to watch for that. Jpg at 11, so I don't think it's that...[a href=\"index.php?act=findpost&pid=158646\"][{POST_SNAPBACK}][/a]

There is a little noise, likely to be invisible in a normal sized print though.

One thing that does intrigue/concern me is a question about how much resolution is needed to benefit from superwides like the Sigma. Although print resolution is limited as prints get bigger I think the loss of detail becomes more and more apparent. Has anyone got any experience of whether this is more of an issue with wide angle lenses than normal and telephoto?

What's up with all those jagged diagonals all over the picture?[a href=\"index.php?act=findpost&pid=158689\"][{POST_SNAPBACK}][/a]

Hmm - good question - actually I pried off the AA filter (not)I'll see what happens in print - my theory would be that they are artefacts of the 100% representation on the web - particularly in the high contrast area of the mullions where it's most obvious. Maybe my capture sharpening was too aggressive - LR doesn't seem to create the same halo artefact so maybe I went a bit overboard.

This may create discordent responses from dedicated users, but I find Focus Magic really tricky to use - it produces halos quite easily. It really can reconstruct detail like nothing else out there, which is excellent for forensic imaging from which the technology derived, but as a tool for *fine art* photography extremely great care is needed using it. I think PK, or the sharpener built into ACR 4.3 is much easier to control and much less prone to this kind of risk.

As for the Sigma, I had one experience like Ray's and I returned the thing. You are very fortunate to have landed on an excellent copy.

I think there is a bit of visble noise at ISO400 in my images too. I've started a thread on that - but I caution I'm nowhere near a landing on this. I'll be posting some further observations in that thread later on tonight. I'm starting to develop some clues about why it happens. On the whole the image clarity from this camera is truly remarkable.

Turns out the jaggies are thanks to Focus Magic. Here's a second file processed without that step. Tonality isn't quite the same since I rebuilt from the ground up.[a href=\"index.php?act=findpost&pid=158806\"][{POST_SNAPBACK}][/a]

I think I preferred the first shot even with the artifacing, the second version looks very video like. And very soft in comparison.

I think this is pretty good copy of a lens with a bit of production quality variation (from what I read). In any event, it's noticeably better than my 16-35 (and Sigma 14 - which goes without saying).[a href=\"index.php?act=findpost&pid=158519\"][{POST_SNAPBACK}][/a]

The main difference is the battery is quite a bit lighter. This translates to a an overall feel that is somewhat lighter. If you were OK with the 1ds2, then the 1ds3 will feel even better. As Michael has noted, the button layout is more intuitive, and combined with "my menu" make the overall ergonomics much better.